The beige walk-through metal detector is part of every air traveler’s life. Now the machine is also part of the collection of the National Museum of American History.

The Transportation Security Administration donated more than two dozen items to the museum Thursday for its official repository of the materials of the terrorist attacks of Sept. 11, 2001, and its aftermath. Several of the TSA items are part of a temporary exhibition, “September 11: Remembrance and Reflection.”

The museum decided to display on open tables more than 50 items that it has collected over the past decade so the public can have unobstructed views. “This is an unprecedented close-up view of the 9/11 objects,” said Marc Pachter, the museum’s interim director.

Because of the special nature of the exhibit and the subject matter, the museum has limited the exhibition to nine days, starting Saturday.

At a Thursday ceremony, TSA Administrator John S. Pistole called for a moment of silence for the victims of the attacks at the World Trade Center and the Pentagon and the Flight 93 plane crash near Shanksville, Pa.

The TSA items in the exhibit include uniforms, gray security-checkpoint containers, confiscated items, a red plastic training weapon, a hand-held metal detector and a training dummy.

The museum has also set out signs from the World Trade Center, a coiled reinforcement bar from the Pentagon and a “call button” from the wreckage of Flight 93.

The exhibition also features excerpts from documentary “9/11: Stories in Fragments,” which will air Monday on the Smithsonian Channel.

Another dimension of the Sept. 11 experience is detailed at the Newseum, which has expanded its FBI exhibit. The new section covers the work of the agency as counterterrorism consumed law enforcement agencies and the focus of the media.

“War on Terror: The FBI’s New Focus” opened Friday. Admission to the Newseum will be free Sept. 10-11.